An Organic Light Emitting Diode (hereinafter referred to as OLED) display panel has advantages such as self-illumination, low energy consumption, no dead angle, fast response and high contrast, and has strong competitiveness as compared with a liquid crystal display panel, so it is believed as a main development trend of the display panel in future. As shown in FIG. 1, the core part of an organic light emitting display panel is an OLED light emitting device with a sandwich structure, comprising a transmission anode 207, an organic material functional layer 208, and a reflection cathode 209.
Wherein, the material for making the transmission anode 207 is usually ITO (Indium Tin Oxide), and the reflection anode 209 comprises a metal reflection layer having a reflection function. The light emitting principle of OLED is to inject carrier holes in the transmission anode 207 and carrier electrons in the reflection cathode 209 to the organic material functional layer 208 by applying working voltages to the transmission anode 207 and the reflection cathode 209, and electrons and holes are composited in the organic material functional layer 208 to form electron-hole pairs and emit visible light from one side of the transmission anode 207.
Currently, the majority of display panels in the market are single-face display panel. In most cases, for example, in advertising facilities of public places such as digital Signage, electronic communication equipments, cashier facilities, window Inquirer facilities, and exhibition buildings, it is generally required to watch pictures displayed on both the front face and the back face of a display panel simultaneously by two persons. However, the double-face display panel in the related art is actually a combination of two independent display panels, and the internal structure thereof and the system for driving the two independent display panels to emit light are complex. This not only increases the production cost of the double-face display panel greatly, but also thickens the product, which does not comply with the trend of making the display panel lighter and thinner. As a result, how to make the whole double-face display panel lighter and thinner and make the driving circuits of the double-face display panel integrated becomes a key problem for development of the double-face display panel.